The present invention relates generally to novel compounds that have affinity for the granulocyte-colony stimulating factor receptor (G-CSFR). More particularly, the invention relates to such compounds which act as G-CSF mimetics by activating or inactivating the G-CSFR, or by affecting ligand binding to G-CSFR. The invention additionally relates to methods of using the novel compounds and pharmaceutical compositions containing a compound of the invention as the active agent. The invention has application in the fields of biochemistry and medicinal chemistry and particularly provides G-CSF mimetics for use in the treatment of human disease.
Granulocyte-colony stimulating factor (G-CSF) is a hematopoietic growth factor that specifically stimulates proliferation and differentiation of cells of the neutrophilic lineage.
G-CSF is a cytokine that binds to and activates the granulocyte-colony stimulating factor receptor (G-CSFR). G-CSFR is expressed on the surface of mature neutrophils and cells committed to the neutrophilic lineage, with receptor density varying from 190 to more than 1400 sites per cell. The receptor is a member of the cytokine receptor superfamily; it contains a cytokine receptor-homologous domain responsible for G-CSF binding, an immunoglobulin-like domain, three fibronectin type III domains, a transmembrane region, and an intracellular domain. The observed affinity of G-CSF for its receptor is about 100 pM.
The complete G-CSF protein has become an important therapeutic agent in clinical indications involving depressed neutrophil counts. Such indications include chemotherapy-induced neutropenia, AIDS and community acquired pneumonia. Furthermore, G-CSF antagonists may be useful in the treatment of some diseases caused by an inappropriate or undesirable activation of G-CSFR.
There remains a need, however, for compounds that bind specifically to G-CSFR, both for studies of the important biological activities mediated by the receptor and for treatment of diseases, disorders and conditions that would benefit from activating or inactivating G-CSFR. The present invention provides such compounds, and also provides pharmaceutical compositions and methods for using the compounds as therapeutic agents.
In one embodiment, the invention provides compounds comprising a peptide chain that binds to G-CSFR. In one aspect, the peptide chain is approximately 10 to 40 amino acids in length and contains a sequence of amino acids of formula (I)
xe2x80x83CX1X2X3X4X5X6X7X8C (SEQ ID NO: 1)xe2x80x83xe2x80x83(I)
wherein each amino acid is indicated by standard one-letter abbreviation, and wherein X1 is A, N, S, F, D, G, L, T, E, V, P, Q, H, M or K; X2 is M, G, R, H, D, I, V, A, S, E, N, F, Y, P, C, W or T; X3 is E, V, W, F, M, A, N, S, L, T, Y, G or P; X4 is V, I, G, Q, W, M, T, Y, L, P, D, C, E or A; X5is M, E, W, L, P, N, I, T, V, F, Y, Q, S, R, W, G, H or D; X6is H, A, W, Y, V, F, Q, M, N, E, S, D, P or G; X7 is M, F, Y, V, N, L, H, D, S, W, G, Q, C or T; and X8 is C, Y, R, I, K, W, L, E, M, H, A, T, F, D, P, G or Q.
In another aspect, the peptide chain is approximately 9 to 40 amino acids in length and contains a sequence of amino acids of formula (II)
XI1XI2XI3SGWVWXI4 (SEQ ID NO: 2)xe2x80x83xe2x80x83(II)
wherein each amino acid is indicated by the standard one-letter abbreviation, and wherein XI1 is S, Q, R, L or Y; XI2 is N, S, T, A or D; XI3 is E, D or N; and XI4 is L V, T, P or H.
In another aspect, the peptide chain is 6 to 40 amino acids in length and contains a sequence of amino acids of formula (III)
ERXII1XII2XII3C (SEQ ID NO: 3)xe2x80x83xe2x80x83(III)
wherein each amino acid is indicated by standard one-letter abbreviation, and wherein XII1 is D, L, S, G, E, A, K or Y; XII2 is W, Y, F, L or V; and XII3 is F, G, M or L.
In still another aspect, the peptide chain is approximately 9 to 40 amino acids in length and contains a sequence of amino acids of formula (IV)
XIII1MVYXIII2XIII3PXIII4W (SEQ ID NO: 4)xe2x80x83xe2x80x83(IV)
wherein each amino acid in indicated by standard one-letter abbreviation, and wherein XII1 is D or E; XIII2 is A or T; XIII3 is Y or V; and XIII4 is P or Y.
In an additional aspect, the invention provides compounds comprising a peptide chain approximately 12 to 40 amino acids in length and contains a sequence of amino acids of formula (V)
CXIV1XIV2XIV3XIV4XIV5XIV6XIV7XIV8XIV9XIV10C (SEQ ID NO: 5)xe2x80x83xe2x80x83(V)
wherein each amino acid is indicated by standard one-letter abbreviation, and wherein XIV1 is E, G, P, N, R, T, W, S, L, H, A, Q or Y; XIV2 is S, T, E, A, D, G, W, P, L, N, V, Y, R or M; XIV3 is R, Y, V, Q, E, T, L, P, S, K, M, A or W; XIV4 is L, M, G, F, W, R, S, V, P, A, D, C or T; XIV5 is V, T, A, R, S, L, W, C, I, E, P, H, F, D or Q; XIV6 is E, Y, G, T, Q, M, S, N, A or P; XIV7 is C, V, D, G, L, W, E, V, I, S, M or A; XIV8 is S, Y, A, W, P, V, L, Q, G, K, F, I, E or D; XIV9 is R, W, M, D, H, V, G, A, Q, L, S, E or Y; XIV10 is M, L, I, S, V, P, W, F, T, Y, R, or Q.
In another aspect the peptide chain is approximately 9 to 40 amino acids in length and contains a sequence of amino acids of formula (VI)
XV1XV2XV3XV4XV5XV6CXV7XV8 (SEQ ID NO: 6)xe2x80x83xe2x80x83(VI)
wherein each amino acid is indicated by standard one-letter abbreviation, and wherein XV1 is E, C, Q, V, or Y; XV2 is E, A, L, M, S, W, or Q; XV3 is K, R or T; XV4 is L, A, or V; XV5 is R, A, M, H, E, V, L, G, D, Q, or S; XV6 is E or V; XV7 is A or G; XV8 is R H, G or L.
In a further aspect, the peptide chain is approximately 10 to 40 amino acids in length that binds to G-CSFR and contains a sequence of amino acids of formula (VII)
XVI1XVI2XVI3XVI4XVI5EXVI6XVI7XVI8XVI9 (SEQ ID NO: 7)xe2x80x83xe2x80x83(VII)
wherein each amino acid is indicated by standard one-letter abbreviation, and wherein XVI5 is A, E or G; XVI2 is E, H or D; XVI3 is R or G; XVI4 is K, Y, M, N, Q, R, D, I, S or E; XVI5 is A, S or P; XVI6 is E, D, T, Q, K or A: XVI7 is R, W, K, L, S, A or Q; XVI8 is R or E; and XVI9 is W, G, or R.
In a final aspect, the invention also provides peptides that, while not necessarily corresponding to one of the above-defined formulas, bind to G-CSFR.
In some contexts, the compounds of the invention are preferably in the form of a dimer. It is also preferred, in some contexts, that the compounds of the invention include a peptide wherein the N-terminus of the peptide is coupled to a polyethylene glycol molecule. In some contexts, it is preferred that the compounds of the invention include a peptide wherein the N-terminus of the peptide is acetylated. In addition, it is preferred, in some contexts, that the compounds of the invention include a peptide wherein the C-terminus of the peptide is amidated.
The invention also provides a pharmaceutical composition that comprises a therapeutically effective amount of a compound of the invention in combination with a pharmaceutically acceptable carrier, as well as a method for treating a patient who would benefit from a G-CSFR modulator, the method comprising administering to the patient a therapeutically effective amount of a compound of the present invention.